Anticancer agents are formulations designed to suppress proliferation of cancer cells and, finally, to halt their proliferation or kill them. Their mechanism of action is to invade the target cancer cells and inhibit replication or synthesis of the cellular DNA, inhibit microtubule formation (inhibit cell division), inhibit intracellular metabolism or regulate nutrient-supplying blood flow. Anticancer agents act on malignant transformed cells in this way, provoking cell death by apoptosis or the like, but at the same time they also exhibit high toxicity for normal cells. Caution must therefore be taken when dealing with anticancer agents.
Currently, many chemotherapeutic methods are being adopted that make use of anticancer agents that can be applied for different types of cancer. For anticancer agent therapy, dosages of the anticancer agents are determined by a physician as appropriate for different patients, and are dispensed into a drip infusion container (infusion bag) by a pharmacist based on the prescription. During the operation of preparing an anticancer agent, primary exposure often occurs when droplets or aerosol of the anticancer agent splashing from the injection needle, chemical bottle and drip-feed solution adhere onto the skin of the pharmacist, or are inhaled through the respiratory organs. In addition, secondary exposure may occur when the medicine bag or bottle that has contacted with splashed droplets of the anticancer agent contacts with the skin of the pharmacist. Preparation of anticancer agents is carried out, for the most part, by professional pharmacists. Consequently, there exists a recognized occupational risk of exposure to anticancer agents by health care professionals such as pharmacists or nurses. In particular, there have been reports of miscarriage, leukemia and bladder cancer among health care professionals themselves, resulting from long-term work activities. Measures against exposure to anticancer agents among health care professionals is therefore an extremely important issue.
Currently, waterproof aprons, double-layer gloves and activated carbon-containing masks are worn during anticancer agent preparation procedures. Anticancer agent preparation procedures are carried out in an environment designed to reduce splashing of chemical agents, such as in a biological safety cabinet that prevents aerosols generated during preparation from flowing to the outside, or in sealed formulating appliances. However, environmental contamination cannot be completely avoided in practice. Anticancer agent preparation procedures have been disclosed that are inventions relating to practice kits and the like, and training is being carried out using such practice kits (see PTL 1). In such cases, an absorbing sheet is spread out on the working bench of the safety cabinet.
Normally, anticancer agent droplets that have splashed during preparation of the anticancer agent adhere onto the working sheet spread out under the working environment, and this is thought to minimize secondary dispersion in the working environment. Under the current guidelines, however, working sheets are designated simply as “having a front surface made of an absorbing material and a back surface made of a chemical agent-impermeable material”. In other words, the current working sheets have not been designed for the express purpose of preparing anticancer agents. Consequently, what are actually being used are substitutes for absorbing sheets, such as surgical sterilized drapes, or pulp sheets intended to absorb blood, body fluid or excreta. The existing working sheets, therefore, are not always adequate for adsorption of anticancer agents.
The following structures are also existing known technologies for absorbing sheets. For example, paper is attached to both sides of a high-water-absorbing material, and a nonwoven fabric is further attached over it, as a laminated sheet (see PTL 2). Another type is a laminated sheet obtained by laminating an activated carbon-containing sheet between two pulp sheets (see PTL 3). While such laminated sheets exhibit an effect for absorption of common fluids such as urine, they are not always sufficient for adsorption of anticancer agent components that have problematic toxicity.
With the existing absorbing sheets, improvement in the absorption (liquid absorption) performance is considered to be equivalent to increasing the amount of liquid absorption. For the purpose of anticancer agent preparation procedures, however, a higher level of performance is required, whereby the solution containing the drug such as an anticancer agent permeates to a suitable extent and is absorbed, and finally retained. While this is obvious, the aspect of higher safety, which is a desired aspect of performance, still cannot be said to be satisfactory. In light of this situation, there is a need for an absorbing sheet that exhibits higher performance specialized for adsorption of highly toxic chemical agents such as anticancer agents, with an aim toward remedying the exposure of health care professionals to the anticancer agents.